Chapter 1 Computers and Digital Basics 1 Chapter

Chapter 1 Computers and Digital Basics

1 Chapter Contents ï Section A: All Things Digital ï Section B: Digital Devices ï Section C: Digital Data Representation ï Section D: Digital Processing ï Section E: Password Security Chapter 1: Computers and Digital Basics 2

1 Fast. Poll True/False Questions Answer A for True and B for False ï 010100 The Web is just another name for the Internet. ï 010200 A computer’s operating system is a type of application software. ï 010300 Microcontrollers are special purpose microprocessors that can be embedded in devices such as refrigerators, cars, and washing machines. ï 010400 A bit is a binary digit, such as a 1 or 0. Chapter 1: Computers and Digital Basics 3

1 Fast. Poll True/False Questions Answer A for True and B for False ï 010500 ASCII, EBCDIC, and Unicode are used to represent character data. ï 010600 A megabyte is 1024 bits. ï 010700 Microprocessors are a type of integrated circuit. ï 010800 C, COBOL, and Java are examples of programming languages. Chapter 1: Computers and Digital Basics 4

1 Fast. Poll True/False Questions Answer A for True and B for False ï 010900 A compiler converts source code to object code. ï 011000 The list of codes for a microprocessor’s instruction set is called machine language. ï 011100 A microprocessor holds data in the interpreter register. ï 011200 A dictionary attack is a virus that hides out in the spelling checker for your word processing software. Chapter 1: Computers and Digital Basics 5

1 A SECTION All Things Digital ï The Digital Revolution ï Convergence ï Digital Society Chapter 1: Computers and Digital Basics 6

1 Question ï 012100 Computers and the digital revolution have changed our lives in many fundamental ways. If you were on the front lines of the digital revolution when computers were first developed to break codes and calculate missile trajectories, you were most likely living in what time period? – – A. B. C. D. World War I The roaring twenties World War II The 1960 s Chapter 1: Computers and Digital Basics 7

1 The Digital Revolution ï The digital revolution is an ongoing process of social, political, and economic change brought about by digital technology, such as computers and the Internet ï Revolves around a constellation of technologies, including digital electronics, computers, communications networks, the Web, and digitization Chapter 1: Computers and Digital Basics 8

1 The Digital Revolution ï Digital electronics use electronic circuits to represent data ï Today, digital electronic devices include computers, portable media players such as i. Pods, digital cameras and camcorders, cell phones, radios and televisions, GPSs, DVD and CD players, e-book readers, digital voice recorders, and handheld gaming consoles Chapter 1: Computers and Digital Basics 9

1 The Digital Revolution Chapter 1: Computers and Digital Basics 10

1 The Digital Revolution ï The second phase of the digital revolution materialized when the Internet was opened to public use – E-mail – Bulletin boards – Chat groups • Blogs – Online social networks Chapter 1: Computers and Digital Basics 11

1 The Digital Revolution ï A computer network is a group of computers linked by wired or wireless technology to share data and resources ï The Web is a collection of linked documents, graphics, and sounds that can be accessed over the Internet ï Cyberspace is a term that refers to entities that exist largely within computer networks ï Digitization is the process of converting text, numbers, sound, photos, and video into data that can be processed by digital devices Chapter 1: Computers and Digital Basics 12

1 Convergence ï Technological convergence is a process by which several technologies with distinct functionalities evolve to form a single product ï Convergence tends to offer enhanced functionality and convenience Chapter 1: Computers and Digital Basics 13

1 Digital Society ï Digital technologies and communications networks make it easy to cross cultural and geographic boundaries ï Anonymous Internet sites, such as Freenet, and anonymizer tools that cloak a person’s identity, even make it possible to exercise freedom of speech in situations where reprisals might repress it ï Citizens of free societies have an expectation of privacy ï Intellectual property refers to the ownership of certain types of information, ideas, or representations Chapter 1: Computers and Digital Basics 14

1 Digital Society ï Digital technology is an important factor in global and national economies, in addition to affecting the economic status of individuals ï Globalization can be defined as the worldwide economic interdependence of countries that occurs as cross-border commerce increases and as money flows more freely among countries ï Individuals are affected by the digital divide, a term that refers to the gap between people who have access to technology and those who do not ï Digital technology permeates the very core of modern life Chapter 1: Computers and Digital Basics 15

1 B SECTION Digital Devices ï Computer Basics ï Personal Computers, Servers, Mainframes, and Supercomputers ï PDAs, Smartphones, and Portable Media Players ï Microcontrollers Chapter 1: Computers and Digital Basics 16

1 Question ï 012200 Today, consumers can choose from a wide variety of digital devices, including personal computers, workstations, videogame consoles, smartphones, i. Pods, and PDAs. Knowing the strengths of these devices helps you make the right choice. What is the fundamental difference between videogame consoles, personal computers, and smartphones? – A. Video game consoles and smartphones are not be classified as computers because they don’t have stored program capabilities like real computers. – B. Videogame consoles and smartphones fill specialized niches and are not replacements for personal computers. – C. Personal computers and smartphones can be used to access the Internet, whereas videogame consoles cannot. – D. Personal computers and smartphones have better graphics than videogame consoles. Chapter 1: Computers and Digital Basics 17

1 Computer Basics ï A computer is a multipurpose device that accepts input, processes data, stores data, and produces output, all according to a series of stored instructions Chapter 1: Computers and Digital Basics 18

1 Computer Basics ï Computer input is whatever is typed, submitted, or transmitted to a computer system ï Output is the result produced by a computer ï Data refers to the symbols that represent facts, objects, and ideas ï Computers manipulate data in many ways, and this manipulation is called processing – Central Processing Unit (CPU) – Microprocessor Chapter 1: Computers and Digital Basics 19

1 Computer Basics ï Memory is an area of a computer that temporarily holds data waiting to be processed, stored, or output ï Storage is the area where data can be left on a permanent basis when it is not immediately needed for processing ï A file is a named collection of data that exists on a storage medium ï The series of instructions that tells a computer how to carry out processing tasks is referred to as a computer program – Software Chapter 1: Computers and Digital Basics 20

1 Computer Basics ï A stored program means that a series of instructions for a computing task can be loaded into a computer’s memory – Allows you to switch between tasks – Distinguishes a computer from other simpler and less versatile devices Chapter 1: Computers and Digital Basics 21

1 Computer Basics ï Application software is a set of computer programs that helps a person carry out a task ï The primary purpose of system software is to help the computer system monitor itself in order to function efficiently – Operating system (OS) Chapter 1: Computers and Digital Basics 22

1 Personal Computers, Servers, Mainframes, and Supercomputers ï A personal computer is a microprocessor-based computing device designed to meet the computing needs of an individual Chapter 1: Computers and Digital Basics 23

1 Personal Computers, Servers, Mainframes, and Supercomputers ï The term workstation has two meanings: – An ordinary personal computer that is connected to a network – A powerful desktop computer used for high-performance tasks Chapter 1: Computers and Digital Basics 24

1 Personal Computers, Servers, Mainframes, and Supercomputers ï A videogame console, such as Nintendo’s Wii, Sony’s Play. Station, or Microsoft’s Xbox, are not generally referred to as personal computers because of their history as dedicated game devices Chapter 1: Computers and Digital Basics 25

1 Personal Computers, Servers, Mainframes, and Supercomputers ï The purpose of a server is to serve computers on a network (such as the Internet or a home network) by supplying them with data ï A mainframe computer (or simply a mainframe) is a large and expensive computer capable of simultaneously processing data for hundreds or thousands of users ï A computer falls into the supercomputer category if it is, at the time of construction, one of the fastest computers in the world – A compute-intensive problem is one that requires massive amounts of data to be processed using complex mathematical calculations Chapter 1: Computers and Digital Basics 26

1 Personal Computers, Servers, Mainframes, and Supercomputers Chapter 1: Computers and Digital Basics 27

1 PDAs, Smartphones, and Portable Media Players ï A PDA (personal digital assistant) is a pocket-sized digital appointment book with a small qwerty keyboard or a touchsensitive screen, designed to run on batteries and be used while holding it ï A handheld computer is essentially a PDA enhanced with features such as removable storage, e-mail, Web access, voice communications, built-in camera, and GPS Chapter 1: Computers and Digital Basics 28

1 PDAs, Smartphones, and Portable Media Players ï A smartphone, which in addition to voice communication, includes features such as full qwerty keypad, text messaging, e-mail, Web access, removable storage, camera, FM radio, digital music player, and software options for games, financial management, personal organizer, GPS, and maps ï i. Pods and similar devices are classified as portable media players because their main strength is playing music, showing videos, and storing photos Chapter ______ 1: ____ Computers ___ and ______ Digital_____ Basics 29

1 PDAs, Smartphones, and Portable Media Players Chapter 1: Computers and Digital Basics 30

1 Microcontrollers ï A microcontroller is a special-purpose microprocessor that is built into the machine it controls ï Microcontrollers can be embedded in all sorts of everyday devices Chapter 1: Computers and Digital Basics 31

1 C SECTION Digital Data Representation ï Data Representation Basics ï Representing Numbers, Text, and Pictures ï Quantifying Bits and Bytes ï Circuits and Chips Chapter 1: Computers and Digital Basics 32

1 Question ï 012300 When you shop for digital devices, their capabilities are often touted in terms of speed and capacity. Suppose you’re shopping for a USB Flash drive. A friend recommends one that’s 64 GB. What does that mean? – – A. B. C. D. It operates at 64 gigabits per second. It holds 64 billion bytes of data. It holds 64 million 0 s and 1 s to represent data. It uses 64 -bit ASCII code to hold data. Chapter 1: Computers and Digital Basics 33

1 Data Representation ï Data representation refers to the form in which data is stored, processed, and transmitted ï Digital devices work with distinct and separate data ï Analog devices work with continuous data Chapter 1: Computers and Digital Basics 34

1 Representing Numbers, Text, and Pictures ï Numeric data – Binary number system ï Character data – ASCII, Extended ASCII, EBCDIC, and Unicode ï Digitizing is the process of converting analog data into digital format Chapter 1: Computers and Digital Basics 35

1 Data Representation Chapter 1: Computers and Digital Basics 36

1 Quantifying Bits and Bytes Chapter 1: Computers and Digital Basics 37

1 Circuits and Chips ï An integrated circuit (computer chip) is a super-thin slice of semiconducting material packed with microscopic circuit elements Chapter 1: Computers and Digital Basics 38

1 Circuits and Chips ï The electronic components of most digital devices are mounted on a circuit board called a system board Chapter 1: Computers and Digital Basics 39

1 D SECTION Digital Processing ï Programs and Instruction Sets ï Processor Logic Chapter 1: Computers and Digital Basics 40

1 Question ï 012400 Programmers write computer programs for word processing, displaying photos, playing music, and showing movies. What programmers write, however, is not what a computer actually processes. Why is the case? – A. Because programmers usually write programs using high-level programming languages that have to be converted into machine language that computers can work with. – B. Because programs are basically outlines that programmers have to fill out using op codes. – C. Because high-level languages are too detailed for computers to process, so programs written in these languages have to be simplified. – D. Because computer programmers make too many errors for programs to run successfully. Chapter 1: Computers and Digital Basics 41

1 Programs and Instruction Sets ï Computers, portable media players, PDAs, and smartphones all work with digital data ï Computer programmers create programs that control digital devices. These programs are usually written in a high-level programming language ï The human-readable version of a program created in a highlevel language by a programmer is called source code Chapter 1: Computers and Digital Basics 42

1 Programs and Instruction Sets Chapter 1: Computers and Digital Basics 43

1 Programs and Instruction Sets ï An instruction set is a collection of preprogrammed activities a microprocessor is hardwired to perform ï Each instruction has a corresponding sequence of 0 s and 1 s ï The end product is called machine code – 1 s and 0 s Chapter 1: Computers and Digital Basics 44

1 Programs and Instruction Sets ï An op code (short for operation code) is a command word for an operation such as add, compare, or jump ï The operand for an instruction specifies the data, or the address of the data, for the operation ï In the following instruction, the op code means add and the operand is 1, so the instruction means Add 1 Chapter 1: Computers and Digital Basics 45

1 Programs and Instruction Sets Chapter 1: Computers and Digital Basics 46

1 Processor Logic ï The ALU (arithmetic logic unit) is the part of the microprocessor that performs arithmetic operations ï The ALU uses registers to hold data that is being processed ï The microprocessor’s control unit fetches each instruction, just as you get each ingredient out of a cupboard or the refrigerator ï The term instruction cycle refers to the process in which a computer executes a single instruction Chapter 1: Computers and Digital Basics 47

1 Processor Logic Chapter 1: Computers and Digital Basics 48

1 Processor Logic Chapter 1: Computers and Digital Basics 49

1 E SECTION Password Security ï Authentication Protocols ï Password Hacks ï Secure Passwords Chapter 1: Computers and Digital Basics 50

1 Question ï 012500 Security experts stress that the use of “strong” passwords can prevent identity theft and help to keep your computer files secure. Which of the following passwords is likely to be the most secure? – A. 12345 because it is all numbers. – B. Hippocampus, because it is a long and unusual word. – C. Il 2 baomw, because it combines numbers with a nonsense word. – D. Football 88, because it combines a word and numbers. Chapter 1: Computers and Digital Basics 51

1 Authentication Protocols ï Security experts use the term authentication protocol to refer to any method that confirms a person’s identity using something the person knows, something the person possesses, or something the person is – A person can also be identified by biometrics, such as a fingerprint, facial features (photo), or retinal pattern – A user ID is a series of characters—letters and possibly numbers or special symbols—that becomes a person’s unique identifier – A password is a series of characters that verifies a user ID and guarantees that you are the person you claim to be Chapter 1: Computers and Digital Basics 52

1 Authentication Protocols Chapter 1: Computers and Digital Basics 53

1 Password Hacks ï When someone gains unauthorized access to your personal data and uses it illegally, it is called identity theft ï Hackers can employ a whole range of ways to steal passwords ï A dictionary attack helps hackers guess your password by stepping through a dictionary containing thousands of the most commonly used passwords ï The brute force attack also uses password-cracking software, but its range is much more extensive than the dictionary attack Chapter 1: Computers and Digital Basics 54

1 Password Hacks ï If hackers can’t guess a password, they can use another technique called sniffing, which intercepts information sent out over computer networks ï An even more sophisticated approach to password theft is phishing ï A keylogger is software that secretly records a user’s keystrokes and sends the information to a hacker Chapter 1: Computers and Digital Basics 55

1 Password Security Chapter 1: Computers and Digital Basics 56

1 Password Security ï Strive to select a unique user ID that you can use for more than one site ï Maintain two or three tiers of passwords Chapter 1: Computers and Digital Basics 57

1 Password Security ï A password manager stores user IDs with their corresponding passwords and automatically fills in login forms Chapter 1: Computers and Digital Basics 58

1 What Do You Think? ï 013100 Should users of location-enabled devices be informed when location tracking is in use? – A. Yes B. No C. Not sure ï 013200 Do you think most people are aware of the privacy issues associated with location-enabled devices? – A. Yes B. No C. Not sure ï 013300 Should users of location-aware devices be permitted to enable and disable tracking features on their devices? – A. Yes B. No Chapter 1: Computers and Digital Basics C. Not sure 59

Chapter 1 Complete Computers and Digital Basics